Halovinylene- 1,2-bis(phosphonic acids and esters)and process for their preparation

ABSTRACT

Halovinylene-1,2-bis(phosphonic acids) and their corresponding esters of the formula   wherein R is hydrogen or a hydrocarbon radical having for example from 1-24 carbon atoms and X is a halogen atom e.g. chlorine or bromine. The halvinylene acids are obtained by hydrolysis of an ethynylene-1,2-bis(phosphonic acid diester) of the formula   with concentrated aqueous haloacid (HX). The acids are useful as flameproofing agents for combustible organic materials, as inhibitors for metal corrosion, as inhibitors for scale formation and as intermediates in the formation of the corresponding monoesters and diesters. The esters are useful as plasticizers, lubricants, lubricant additives and functional fluids.

United States Patent [1 1 Maier 1 1 HALOVINYLENE- l,2-BIS(PHOSPHONIC ACIDS AND ESTERS)AND PROCESS FOR THEIR PREPARATION [75] Inventor: Ludwig Maier, Kilchberg,

Switzerland [73] Assignee: Monsanto Company, St. Louis, Mo. [22] Filed: Oct. 29, 1973 [21] Appl. No.: 410,651

Related US. Application Data [62] Division of Ser. No. 261,171, June 9, 1972, Pat. No.

[30] Foreign Application Priority Data June 30, 1971 Switzerland H 9591/71 [52] US. Cl. 260/502.4 P; 210/58; 252/81;

252/497, 252/78; 252/175; 252/DIG. ll; 260/2 P; 260/4381; 260/439 R; 423/273 1 Dec. 9, 1975 Primary Examiner-Joseph E. Evans [57] ABSTRACT Halovinylene-l,2-bis(phosphonic acids) and their corresponding esters of the formula wherein R is hydrogen or a hydrocarbon radical having for example from 1-24 carbon atoms and X is a halogen atom e.g. chlorine or bromine, The halvinylene acids are obtained by hydrolysis of an ethynylene-l,2-bis(phosphonic acid diester) of the formula with concentrated aqueous haloacid (HXL The acids are useful as flameproofing agents for combustible organic materials, as inhibitors for metal corrosion, as inhibitors for scale formation and as intermediates in the formation of the corresponding monoesters and diesters. The esters are useful as plasticizers, lubricants, lubricant additives and functional fluids.

2 Claims, N0 Drawings 1 IIALOVINYLENE- l,2-BIS(PHOSPI'IONIC ACIDS AND ESTERS)AND PROCESS FOR THEIR PREPARATION This is a division of application Ser. No. 261,171, filed June 9, 1972, now US. Pat. No. 3,789,092.

BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to halovinylene-l,2-bis(phosphonic acids) and esters thereof of the formula H x 1 l l wherein R is a hydrocarbon radical having, for example, l-24 carbon atoms or hydrogen and X is halogen radical. In a further aspect this invention relates to a process for preparing said acids by hydrolysis of an ethynylene-l ,2-bis(phosphonic acid diester) of the formula wherein R is a hydrocarbon radical having, for example, l24 carbon atoms.

2. Description of the Prior Art:

It is known that certain phosphonic acid esters can be hydrolyzed with concentrated hydrochloric acid to corresponding phosphonic acids.

SUMMARY OF THE INVENTION It has been discovered in accordance with the present invention that halovinylene-l,2-bis(phosphonic acids) of the formula H x0 I I l are obtained by hydrolysis of an ethynylene-l,2-bis(- phosphinic acid diester) of the formula with concentrated aqueous haloacid. It is surprising that the hydrolysis results in the production of halovinylene-l ,2-bis(phosphonic acids) instead of the expected ethylnylenel ,2-bis(phosphonic acid). The process of the present invention thus unexpectedly results in the addition of halide to the acetylenic bond.

DETAILED DESCRIPTION In carrying out the process of the present invention ethylnylenel,2-bis(phosphonic diester) is heated with concentrated aqueous haloacid until cleavage is complete. The hydrolysis, which occurs simultaneously with addition of halide to the acetylenic bond, occurs as follows:

ill

preferably, the released alcohol is continuously removed from the reaction mixture. The thus formed halovinylene-l,2-bislphosphinic acid) can be separated from the reaction mixture by any suitable procedure, such as, for example, by evaporating water and unreacted haloacid.

In the process of the present invention any suitable haloacid can be employed with suitable acids including hydroiodic, hydrofluoric, hydrochloric and hydrobromic acid.

Hydrochloric acid and hydrobromic acid are generally preferred.

The ethynylene-l,2-bis(phosphonic acid diesters) employed as starting materials in the process of the present invention of the formula l (R'Ohl C CFkOR'),

wherein R is a hydrocarbon radical having for example, 1-24 carbon atoms such as for example, alkaryl, aryl, higher alkyl, lower alkyl l4 carbon atoms) allyl, and cycloalkyl. The lower alkyl esters are the most con veniently used starting compounds in the process of the present invention since the alcohols obtained by the reaction are easily split off and removed from the reaction medium. This class of compounds and their preparation are known to the art. (8.]. Ionin and AA. Petrov, Zh. Obschch. Khim. 35 (I965), S p 19l7).

The halovinylenel,2-bis(phosphonic acids) of the present invention which have a nonhydrolyzable halogen atom are useful for flameproofing combustible organic materials, as corrosion inhibitors and chelating or complexing agents for sequesting metal ions such as calcium magnesium, iron, copper etc., as detergent additives in measured amounts for the prevention of precipitation and scale formation in hard" water, and as stabilizers for peroxide and active chlorine compound bleaching agents. The halovinylene-l ,2-bis(phosphonic acids) can be polymerized by standard polymerization methods and can also be esterified to the corresponding diesters using well-known esterification methods such as, for example, heating the acid with an orthoformic acid ester.

The diesters of the present invention are represented by the formula OH X0 uuo ac di tom), wherein X is defined as above and R is a hydrocarbon radical for example, alkaryl, aryl, lower alkyl, higher alkyl, alkyl and cycloalkyl with the R group being conveniently derived from an alcohol known to occur in a phosphonate.

Examples of halovinylene-l ,2-bis( phosphonic diesters) which can be prepared in accordance with thepresent invention include fluoro-, bromo, iodoand chlorovinylenel ,2-bis( phosphonic dimethylester), chlorovin ylenel ,2-bis( phosphonic diethylester), chlorovin ylenel ,2-bis( phosphonic di-n-propylester 3 chlorovinylene-l ,2-bis(phosphonic di-iso-propylester), chlorovinylene- 1 ,2-bis(phosphonic di-n-butylester), chlorovinylenel ,2-bis(phosphonic di-iso-butylester), chlorovinylenel ,2-bis(phosphonic di-tert-butylester), chlorovinylenel .2-bis( phosphonic diallylester), chlorovinylenel ,2-bis( phosphonic divinylester), chlorovinylene- 1 ,2'bis( phosphonic didodecylester), chlorovinylenel ,2-bis( phosphonic dioleylester), chlorovinylene- 1 ,2bis( phosphonic distearylester), chlorovinylenel ,2-bis( phosphonic dieicosylester), chlorovinylene l ,2-bis( phosphonic dibenzylester), chlorovinylenel ,2-bis(phosphonic diphenylester), chlorovinylenel ,2-bis(phosphonic di-tert-butylphenylester), chlorovinylene- 1 ,2-bis( phosphonic di-a-naphthylester, chlorovinylenel ,2-bis(phosphonic di-B-naphthylester), chlorovinylene-1,2-bis(phosphonic lester), chlorovinylenel ,2-bis( phosphonic dicyclohexadieny' lester) and the like.

It is understood that the halovinylene-l,2-bis(phosphonic diester) may also show a combination of different ester groups.

The halovinylene-l,2-bis(phosphonic acid esters) of the present invention are useful as plasticizers, as lubricants or lubricant additives, and as fuctional fluids, such as hydraulics and heat transfer agents.

The halovinylene-l,2-bis(phosphonic acids) of the present invention can also be converted to the so-called half-esters of the formula dicyclopentywherein R and X are defined as above. These halovinylene-l ,2-bis(phosphonic monoesters) are conveniently prepared by heating halovinylene-l ,2-bis(phosphonic acid) together with halovinylene-l,2-bis(phosphonic acid diesters) in the presence of a transesterification catalyst preferably using about equimolar quantities of the acid and diester reactants.

The following preparations and examples illustrate specific embodiments of the invention.

Prep aration The starting compound ethnylene-l,2-bis(phosphonic diethylester) is prepared in accordance with the cited literature reference as follows:

To an ether solution of 9.4 g(0.1 mol) of ClC=CCl are added 16.6 g (0.1 mol) of l=(OC'r,,H at 5 and the mixture is subsequently refluxed for l hour. Upon distillation of the ether 15.9 g (81%) of ClC=CP(O)- (OC H remains as a residue. To this residue are added 16.6 g (0.1 mol) of P(OC H whereby an exothermic reaction occurs and the temperature rises to about 90C. The mixture is cooled with ice. It is left to stand over night at room temperature and then distilled. Eleven point six grams (48%) of C H O) PC CP(OC H is obtained as a colorless liquid, b.p. l45C/0.00l mm, n 1.4470. 31p chemi cal shift l 1 ppm, H-NMR (in CDCl;,): CH at 1.36 ppm (J 7 cps, 12 H), CH at 4.20 ppm (J 7,.l cps, 8 H) Literature: b.p. 181.5-1 85C/2.5 mm, n 1.4475.

EXAMPLE 1 A mixture consisting of 5 g ethynylene-l ,2-bis(phosphonic diethylester) and 50 ml of concentrated HCl is refluxed for 14 hours and then evaporated to dryness thereby to obtain 3.74 g (l00%) crystals of which can be titrated as a tetrabasic acid. (Equivalent weight found 59.7, calculated 55.6.) HNMR (in D 0): CH at 7.32 ppm (broad, Jpf l4 cps) and OH at 6.45 ppm (broad, singulet).]

EXAMPLE 2 A mixture consisting of 3.75 g of chlorovinylene-1,2- bis(phosphonic acid) and 40 ml of HC(OC H is refluxed for 3 hours and then fractionally distilled thereby to obtain 2.45 g (43%) of (C H O) PCH=CC!- P(OC H b.p. l30/0.001 mm. H--NMR (in CDCI ):CH at 1.33 ppm (J 7 cps, 12H), CH at 4.17 ppm (J 7, J S cps, 8 H) and CH at 7.0 ppm (J l2, JP CpS, l H

C H Cl0 P calcd C 35.88; H627; cl 10.59. found C 35.92; H 6.34; Cl 10.52.

The thus obtained chlorovinylene-l,2-bis(phosphonic acid diethylester) is reacted under transesterification conditions with the chlorovinylene-l ,2-bis(- phosphonic acid) of Example 1 to obtain the corresponding half-ester.

EXAMPLE 3 A mixture consisting of 5 g and 50 ml of 40% aqueous solution of HBr is refluxed for 15 hours, evaporated in a rotating evaporator and made completely anhydrous by azetropic benzene distillation.

where X is selected from the group consisting of chlorine, bromine and iodine.

2. The compound of claim 1 wherein X represents chlorine or bromine. 

1. A HALOVINYLENE-1,2-BIS(PHOSPHONIC ACID) OF THE FORMULA 8N
 2. The compound of claim 1 wherein X represents chlorine or bromine. 